This example presents an interactive scatter plot of the Iris dataset, where dropdown menus let users switch which attributes map to the X and Y axes. Built with D3 v6, the visualization animates point positions and axis scales over one second using `transition()`, while the HTML menus are created with a custom `menu()` component that dispatches change events. SVG circles grow from a zero radius on entry, and the plot is rendered using scaleLinear, axisLeft, and axisBottom.